#ifndef LLVM_CODEGEN_SPLITKIT_H
#define LLVM_CODEGEN_SPLITKIT_H
+#include "LiveRangeCalc.h"
#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/IndexedMap.h"
#include "llvm/ADT/IntervalMap.h"
#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/CodeGen/SlotIndexes.h"
namespace llvm {
class VNInfo;
class raw_ostream;
-/// At some point we should just include MachineDominators.h:
-class MachineDominatorTree;
-template <class NodeT> class DomTreeNodeBase;
-typedef DomTreeNodeBase<MachineBasicBlock> MachineDomTreeNode;
-
-
/// SplitAnalysis - Analyze a LiveInterval, looking for live range splitting
/// opportunities.
class SplitAnalysis {
/// Idx.
RegAssignMap RegAssign;
- typedef DenseMap<std::pair<unsigned, unsigned>, VNInfo*> ValueMap;
+ typedef PointerIntPair<VNInfo*, 1> ValueForcePair;
+ typedef DenseMap<std::pair<unsigned, unsigned>, ValueForcePair> ValueMap;
/// Values - keep track of the mapping from parent values to values in the new
/// intervals. Given a pair (RegIdx, ParentVNI->id), Values contains:
///
/// 1. No entry - the value is not mapped to Edit.get(RegIdx).
- /// 2. Null - the value is mapped to multiple values in Edit.get(RegIdx).
- /// Each value is represented by a minimal live range at its def.
- /// 3. A non-null VNInfo - the value is mapped to a single new value.
+ /// 2. (Null, false) - the value is mapped to multiple values in
+ /// Edit.get(RegIdx). Each value is represented by a minimal live range at
+ /// its def. The full live range can be inferred exactly from the range
+ /// of RegIdx in RegAssign.
+ /// 3. (Null, true). As above, but the ranges in RegAssign are too large, and
+ /// the live range must be recomputed using LiveRangeCalc::extend().
+ /// 4. (VNI, false) The value is mapped to a single new value.
/// The new value has no live ranges anywhere.
ValueMap Values;
- typedef std::pair<VNInfo*, MachineDomTreeNode*> LiveOutPair;
- typedef IndexedMap<LiveOutPair, MBB2NumberFunctor> LiveOutMap;
-
- // LiveOutCache - Map each basic block where a new register is live out to the
- // live-out value and its defining block.
- // One of these conditions shall be true:
- //
- // 1. !LiveOutSeen.count(MBB->getNumber())
- // 2. LiveOutCache[MBB].second.getNode() == MBB
- // 3. forall P in preds(MBB): LiveOutCache[P] == LiveOutCache[MBB]
- //
- // This is only a cache, the values can be computed as:
- //
- // VNI = Edit.get(RegIdx)->getVNInfoAt(LIS.getMBBEndIdx(MBB))
- // Node = mbt_[LIS.getMBBFromIndex(VNI->def)]
- //
- // The cache can be shared by all the new registers because at most one is
- // live out of each block.
- LiveOutMap LiveOutCache;
-
- // LiveOutSeen - Indexed by MBB->getNumber(), a bit is set for each valid
- // entry in LiveOutCache. This is also used as a visited set for
- // findReachingDefs().
- BitVector LiveOutSeen;
-
- /// LiveInBlock - Info for updateSSA() about a block where a register is
- /// live-in.
- /// The updateSSA caller provides DomNode and Kill inside MBB, updateSSA()
- /// adds the computed live-in value.
- struct LiveInBlock {
- // Dominator tree node for the block.
- // Cleared by updateSSA when the final value has been determined.
- MachineDomTreeNode *DomNode;
-
- // Live-in value filled in by updateSSA once it is known.
- VNInfo *Value;
-
- // Position in block where the live-in range ends, or SlotIndex() if the
- // range passes through the block.
- SlotIndex Kill;
-
- LiveInBlock(MachineDomTreeNode *node) : DomNode(node), Value(0) {}
- };
+ /// LRCalc - Cache for computing live ranges and SSA update. Each instance
+ /// can only handle non-overlapping live ranges, so use a separate
+ /// LiveRangeCalc instance for the complement interval when in spill mode.
+ LiveRangeCalc LRCalc[2];
- /// LiveInBlocks - List of live-in blocks used by findReachingDefs() and
- /// updateSSA(). This list is usually empty, it exists here to avoid frequent
- /// reallocations.
- SmallVector<LiveInBlock, 16> LiveInBlocks;
+ /// getLRCalc - Return the LRCalc to use for RegIdx. In spill mode, the
+ /// complement interval can overlap the other intervals, so it gets its own
+ /// LRCalc instance. When not in spill mode, all intervals can share one.
+ LiveRangeCalc &getLRCalc(unsigned RegIdx) {
+ return LRCalc[SpillMode != SM_Partition && RegIdx != 0];
+ }
/// defValue - define a value in RegIdx from ParentVNI at Idx.
/// Idx does not have to be ParentVNI->def, but it must be contained within
/// Return the new LI value.
VNInfo *defValue(unsigned RegIdx, const VNInfo *ParentVNI, SlotIndex Idx);
- /// markComplexMapped - Mark ParentVNI as complex mapped in RegIdx regardless
- /// of the number of defs.
- void markComplexMapped(unsigned RegIdx, const VNInfo *ParentVNI);
+ /// forceRecompute - Force the live range of ParentVNI in RegIdx to be
+ /// recomputed by LiveRangeCalc::extend regardless of the number of defs.
+ /// This is used for values whose live range doesn't match RegAssign exactly.
+ /// They could have rematerialized, or back-copies may have been moved.
+ void forceRecompute(unsigned RegIdx, const VNInfo *ParentVNI);
/// defFromParent - Define Reg from ParentVNI at UseIdx using either
/// rematerialization or a COPY from parent. Return the new value.
MachineBasicBlock &MBB,
MachineBasicBlock::iterator I);
- /// extendRange - Extend the live range of Edit.get(RegIdx) so it reaches Idx.
- /// Insert PHIDefs as needed to preserve SSA form.
- void extendRange(unsigned RegIdx, SlotIndex Idx);
-
- /// findReachingDefs - Starting from MBB, add blocks to LiveInBlocks until all
- /// reaching defs for LI are found.
- /// @param LI Live interval whose value is needed.
- /// @param MBB Block where LI should be live-in.
- /// @param Kill Kill point in MBB.
- /// @return Unique value seen, or NULL.
- VNInfo *findReachingDefs(LiveInterval *LI, MachineBasicBlock *MBB,
- SlotIndex Kill);
-
- /// updateSSA - Compute and insert PHIDefs such that all blocks in
- // LiveInBlocks get a known live-in value. Add live ranges to the blocks.
- void updateSSA();
+ /// removeBackCopies - Remove the copy instructions that defines the values
+ /// in the vector in the complement interval.
+ void removeBackCopies(SmallVectorImpl<VNInfo*> &Copies);
+
+ /// getShallowDominator - Returns the least busy dominator of MBB that is
+ /// also dominated by DefMBB. Busy is measured by loop depth.
+ MachineBasicBlock *findShallowDominator(MachineBasicBlock *MBB,
+ MachineBasicBlock *DefMBB);
+
+ /// hoistCopiesForSize - Hoist back-copies to the complement interval in a
+ /// way that minimizes code size. This implements the SM_Size spill mode.
+ void hoistCopiesForSize();
/// transferValues - Transfer values to the new ranges.
/// Return true if any ranges were skipped.
projects / oota-llvm.git / blobdiff